21124331240 has 128 divisors (see below), whose sum is σ = 52147307520. Its totient is φ = 7666790400.

The previous prime is 21124331203. The next prime is 21124331251. The reversal of 21124331240 is 4213342112.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5963870 + ... + 5967410.

It is an arithmetic number, because the mean of its divisors is an integer number (407400840).

Almost surely, 2^21124331240 is an apocalyptic number.

21124331240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21124331240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26073653760).

21124331240 is an abundant number, since it is smaller than the sum of its proper divisors (31022976280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21124331240 is a wasteful number, since it uses less digits than its factorization.

21124331240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3883 (or 3879 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21124331240 its reverse (4213342112), we get a palindrome (25337673352).

The spelling of 21124331240 in words is "twenty-one billion, one hundred twenty-four million, three hundred thirty-one thousand, two hundred forty".